If Putin's wife ran the largest investment fund in Russia would you consider that only a bit suspect?

If she were siphoning off money she would not be doing it an obvious way and we likely wouldn't hear about it. They have a habit of bankrupting wannabe woodward and Bernsteins and taking large sums of money from foreign news organizations that say the "wrong" thing:

https://www.irrawaddy.com/news/asia/in-singapore-the-economi...

Singapore is definitely good at rooting out low level corruption though.